Hydraulically balanced pump discharge

ABSTRACT

A horizontal pumping system for pumping fluids into downstream piping includes a motor and a pump driven by the motor. The pump includes a discharge assembly for use in connecting a pump within a horizontal pumping system to downstream piping. The discharge assembly preferably includes a discharge head and a stub end configured for sliding engagement with the discharge head. The stub end is captured within the discharge head in a hydraulically balanced condition and the discharge assembly further includes a hydraulic balance chamber and a runner plate within the hydraulic balance chamber. The runner plate is secured to the stub end.

FIELD OF THE INVENTION

This invention relates generally to the field of pumping systems, and more particularly, but not by way of limitation, to a mechanism for connecting the discharge of a pumping system to a downstream line.

BACKGROUND

Horizontal pumping systems are used in various industries for a variety of purposes. For example, in the oil and gas industry horizontal pumping systems are used to pump fluids, such as water separated from oil, to a remote destination, such as a tank or disposal well. Typically these horizontal pumping systems include a pump, a motor, and a suction housing positioned between the pump and the motor. A thrust chamber is also included between the motor and the suction housing. The pump includes a discharge assembly that is connected to downstream piping.

As illustrated in the PRIOR ART drawing of FIG. 1, a typical prior art surface pumping system 500 includes a discharge head 502 and a stub end 504 that is threadingly engaged within the discharge head 502. The stub end 504 can be connected to a flange 506 that is in turn connected to downstream piping 508. Once the stub end 504 is threaded into the discharge head 502 and then connected to the flange 506 and downstream piping 508, there is little or no degree of axial movement between the pumping system 500 and the downstream piping 508. The lack of movement between the pumping system 500 and the downstream piping 508 creates a challenge during installation of the pumping system 500 because the components must be precisely manufactured and aligned during installation. Furthermore, during use the components may expand and contract due to changes in operating and environmental temperatures. The expansion and contraction of the downstream piping 508 and the pumping system 500 may strain the components and connections. There is, therefore, a need for an improved system of connecting downstream piping to a horizontal pumping system that alleviates the deficiencies of the prior art.

SUMMARY OF THE INVENTION

In an embodiment, the present invention includes a horizontal pumping system for pumping fluids into downstream piping. The horizontal pumping system includes a motor and a pump driven by the motor. The pump includes a discharge assembly for use in connecting a pump within a horizontal pumping system to downstream piping. The discharge assembly includes a discharge head and a stub end configured for sliding engagement with the discharge head.

In an embodiment, the stub end is captured within the discharge head in a hydraulically balanced condition. The discharge assembly includes a hydraulic balance chamber and a runner plate within the hydraulic balance chamber. The runner plate is secured to the stub end.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a PRIOR ART horizontal pumping system.

FIG. 2 is a side view of a horizontal pumping system constructed in accordance with an embodiment.

FIG. 3 is a cross-sectional view of the discharge assembly connection constructed in accordance with a first embodiment in a first position.

FIG. 4 is a cross-sectional view of the discharge assembly connection constructed in accordance with a first embodiment in a second position.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with an embodiment of the present invention, FIG. 2 shows a side view of a horizontal pumping system 100. The horizontal pumping system 100 includes a motor 102, a suction housing 104, a pump 106, a thrust chamber 108, a frame 110 and a pad 112. The suction housing 104 is connected between the pump 106 and the thrust chamber 108. The thrust chamber 108 is connected between the suction housing 104 and the motor 102. Generally, the motor 102 drives the pump 106 through a series of shafts (not visible in FIG. 1) that extend through the thrust chamber 108 and suction housing 104. Pumped fluids are provided to the suction housing 104 and pressurized by the pump 106. In an embodiment, the pump 106 is a centrifugal pump. In an embodiment, the pump 106 is a multistage centrifugal pump. Each of the components within the horizontal pumping system 100 is in an embodiment supported by the frame 110, which is in turn supported by the pad 112. Although only one of each component is shown in FIG. 2, it will be understood that more can be connected when appropriate, that other arrangements of the components are desirable and that these additional configurations are encompassed within the scope in an embodiment.

The pump 106 includes a discharge assembly 114 that is connected to downstream piping 116. As used herein, the term downstream piping 116 may refer to tubing, pipes, hoses or other fixed facilities, including tanks and vessels.

Turning to FIGS. 3 and 4, shown therein are cross-sectional views of the discharge assembly 114 constructed in accordance with in an embodiment. FIG. 3 presents the discharge assembly 114 in a contracted first position and FIG. 4 presents the discharge assembly 114 in a second expanded position. The discharge assembly 114 generally permits a degree of axial and rotational movement between the pump 106 and the downstream piping 116. Accommodating a degree of movement between the pump 106 and the downstream piping 116 facilitates the alignment and installation of the horizontal pumping system 100 and also decreases any strain that results from the expansion and contraction of the horizontal pumping system 100 and downstream piping 116 during use.

In an embodiment, the discharge assembly 114 includes a discharge head 118, a stub end 120, a runner plate 122 and an end plate 124. The discharge head 118 includes an interior passage 126 through which pumped fluids will pass under pressure. In an embodiment, the interior passage 126 has a circular cross-section. It will be understood that the interior passage within the discharge head 118 may be a different size and configuration than the balance of the pump 106. The discharge head 118 further includes a hydraulic balance chamber 128 adjacent the open end of the discharge head 118.

The stub end 120 includes a proximal portion 130, a distal portion 132 and a shoulder 134 that separates the proximal portion 130 from the distal portion 132. The proximal portion 130 is sized and geometrically configured to be slidingly received within the interior passage 126. The distal portion 132 of the stub end 120 is configured for connection to an intermediate flange (not shown) or directly to the downstream piping 116.

The runner plate 122 is sized to fit around the external surface of the proximal portion 130 and within the interior surface of the hydraulic balance chamber 128. The runner plate 122 is captured against the shoulder 134 by a lock 136. In an embodiment, the lock 136 is a nut or washer that is configured for threaded engagement with the stub end 120. Although a locking nut is in an embodiment, it will be appreciated that the lock 136 may alternatively incorporate alternative locking mechanisms that include, for example, snap rings, compression fittings and pins.

The end plate 124 surrounds the exterior of the distal portion 132 of the stub end 120 and is secured to the discharge head 118 with fasteners 138. The end plate 124 limits the extension of the stub end 120 as the runner plate 122 comes into contact with the end plate 124. The end plate 124 cooperates with the discharge head 118 and stub end 120 to define the interior boundaries of the hydraulic balance chamber 128.

The hydraulic balance chamber 128 is divided by the runner plate 122 into a high pressure chamber 140 and a low pressure chamber 142. The high pressure chamber 140 is placed into fluid communication with the pumped fluid within the stub end 120 by a pressure port 144. The low pressure chamber 142 is placed into fluid communication with external ambient pressure through a vent 146.

In an embodiment, the cross-sectional area of the high pressure chamber 140 (A1) is substantially the same as the cross-sectional area of the end wall of the proximal portion 130 of the stub end 120 (A2). In this way, the pressure applied to the end of the proximal portion 130 of the stub end 120 is approximately the same as the pressure applied in the opposite direction on the runner plate 122 within the high pressure chamber 140 of the hydraulic balance camber 128.

Seals 148 prevent fluid from passing out of the hydraulic balance chamber 128 and across the runner plate 122 within the hydraulic balance chamber 128. The seals 148 may be O-ring seals, lip seals, spring seals, shaft seals or mechanical seals. It will be appreciated that additional or fewer seals 148 may be used within the discharge assembly 114 and that the seals 148 may include a combination of a variety of different types of seals.

During operation of the horizontal pumping system 100, pressurized fluid applies forces in substantially equal magnitudes in opposite directions to the stub end 120. This permits the stub end 120 to slide without substantial restriction from pressure within the discharge head 118. Allowing the stub end 120 to move axially and rotationally within the fixed discharge head 118 facilitates alignment and connection of the downstream piping 116 and reduces strain caused by relative expansion and contraction of the components within the horizontal pumping system 100 and the downstream piping 116.

It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and functions of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. It will be appreciated by those skilled in the art that the teachings of the present invention can be applied to other systems without departing from the scope and spirit of the present invention. This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A discharge assembly for use in connecting a pump within a horizontal pumping system to downstream piping, the discharge assembly comprising: a discharge head; and a stub end configured for sliding engagement with the discharge head.
 2. The discharge assembly of claim 1, wherein the discharge assembly further comprises: a hydraulic balance chamber; and a runner plate within the hydraulic balance chamber, wherein the runner plate is secured to the stub end.
 3. The discharge assembly of claim 2, wherein the hydraulic balance chamber comprises: a high pressure chamber; and a low pressure chamber.
 4. The discharge assembly of claim 3, wherein the stub end comprises: an interior; and a pressure port that places the high pressure chamber in fluid communication with the interior.
 5. The discharge assembly of claim 3, wherein the stub end has a proximal end wall that has a stub end cross-sectional area, and wherein the high pressure chamber has a cross-sectional area that is substantially the same as the stub end cross-sectional area.
 6. The discharge assembly of claim 3, wherein the discharge head includes a vent that places the low pressure chamber in fluid communication with an external atmosphere.
 7. The discharge assembly of claim 2, wherein the runner plate is secured to the stub end with a lock selected from the group consisting of locking nuts, snap rings, dowels and press fit connections.
 8. A horizontal pumping system for pumping fluids into downstream piping, the horizontal pumping system comprising: a motor; and a pump driven by the motor, wherein the pump comprises: a discharge assembly for use in connecting a pump within a horizontal pumping system to downstream piping, wherein the discharge assembly comprises: a discharge head; and a stub end configured for sliding engagement with the discharge head.
 9. The horizontal pumping system of claim 8, wherein the discharge assembly further comprises: a hydraulic balance chamber; and a runner plate within the hydraulic balance chamber, wherein the runner plate is secured to the stub end.
 10. The horizontal pumping system of claim 9, wherein the hydraulic balance chamber comprises: a high pressure chamber; and a low pressure chamber.
 11. The horizontal pumping system of claim 10, wherein the stub end comprises: an interior; and a pressure port that places the high pressure chamber in fluid communication with the interior.
 12. The horizontal pumping system of claim 10, wherein the stub end has a proximal end wall that has a stub end cross-sectional area, and wherein the high pressure chamber has a cross-sectional area that is substantially the same as the stub end cross-sectional area.
 13. The horizontal pumping system of claim 10, wherein the discharge head includes a vent that places the low pressure chamber in fluid communication with an external atmosphere.
 14. The horizontal pumping system of claim 10, wherein the runner plate is secured to the stub end with a lock selected from the group consisting of locking nuts, snap rings, dowels and press fit connections.
 15. A horizontal pumping system for pumping fluids into downstream piping, the horizontal pumping system comprising: a motor; and a pump driven by the motor, wherein the pump comprises: a discharge head; and a stub end that is axially and rotationally movable within the discharge head.
 16. The horizontal pumping system of claim 15, wherein the pump further comprises: a hydraulic balance chamber within the discharge head; and a runner plate within the hydraulic balance chamber.
 17. The horizontal pumping system of claim 16, further comprising an end plate that captures the stub end within the discharge head.
 18. The horizontal pumping system of claim 16, wherein the hydraulic balance chamber comprises: a high pressure chamber; a low pressure chamber; and wherein the high pressure chamber is separated from the low pressure chamber by the runner plate.
 19. The horizontal pumping system of claim 18, wherein the stub end includes a pressure port in communication with the high pressure chamber.
 20. The horizontal pumping system of claim 18, wherein the discharge head includes a vent extending between the low pressure chamber and an external ambient pressure. 